This invention relates to a file management method and system for managing files, and in particular to a file management system for managing file attributes in a file server, etc., for managing files shared on a network.
In recent years, a client and server system wherein a plurality of clients and a plurality of servers that can be provided by workstations or personal computers are connected to each other by a local area network (LAN) has come into wide spread use. In the system, it is a file server that particularly manages files shared on the network.
The file server adopts a general file system such as a UNIX (a trademark of Novell, Inc.) file system or DFR (document filing and retrieval). In such a file system, generally it is considered that a file is made up of a content section indicating actual data and an attribute section of additional information such as a title given thereto. Further, the attributes in the attribute section of the file can be roughly classified into those managed by the server and those managed by the user.
The attributes managed by the server are "creation time of day," "creator name," etc., for example,; even if the user does not explicitly specify them, the file system automatically sets their values. For example, when a file is created, automatically the UNIX file system sets information such as "creator," "creation time of day," "creator group," and "file identifier" without explicit specification of the user. Other file systems also set similar attributes automatically.
On the other hand, the attributes managed by the user are "title," "retrieval keyword," etc., for example. "Extended attribute," etc., in DFR is also an example of the attributes managed by the user. The file system does not interpret the contents of the attributes managed by the user and the attribute values can be set only by the user who explicitly specifies them.
Thus, in the conventional file systems, basically the values of the attributes managed by the server are set and updated by the file system and the values of the attributes managed by the user can be set and updated only by the user who explicitly specifies them.
A system for managing file attributes is described in Japanese Patent Unexamined Publication No. Hei 1-263746, wherein an automatic registered person list management system is disclosed. This automatic registered person list management system comprises a file server for managing files and a certification server for managing a list for enabling access to directories in the file server. When the list in the certification server is changed, an access list in the file server is also changed. Thus, when the registered person list in the certification server is changed, if the registered person changed is used for the directories in the file server, labor for applying the same change of the registered person to all directories including the access list can be saved. Also in this case, the attributes managed by the user are not changed by the server in the file system independently, and are changed only by specification from others, in this case, the certification server.
As described above, the file system of the file server does not take the liberty of changing the attributes managed by the user except that the user gives explicit instruction. Thus, for example, if it is previously known that an attribute value must be changed after a lapse of a given time, the user must change the value explicitly after a lapse of the given time; the load put on the user is large and the mistake of forgetting the change is prone to occur.